Hi Jan,
miquel.raynal@xxxxxxxxxxx wrote on Wed, 29 Sep 2021 00:22:48 +0200:
> Following the introduction of the generic ECC engine infrastructure, it
> was necessary to reorganize the code and move the ECC configuration in
> the ->attach_chip() hook. Failing to do that properly lead to a first
> series of fixes supposed to stabilize the situation. Unfortunately, this
> only fixed the use of software ECC engines, preventing any other kind of
> engine to be used, including on-die ones.
>
> It is now time to (finally) fix the situation by ensuring that we still
> provide a default (eg. software ECC) but will still support different
> ECC engines such as on-die ECC engines if properly described in the
> device tree.
>
> There are no changes needed on the core side in order to do this, but we
> just need to leverage the logic there which allows:
> 1- a subsystem default (set to Host engines in the raw NAND world)
> 2- a driver specific default (here set to software ECC engines)
> 3- any type of engine requested by the user (ie. described in the DT)
>
> As the raw NAND subsystem has not yet been fully converted to the ECC
> engine infrastructure, in order to provide a default ECC engine for this
> driver we need to set chip->ecc.engine_type *before* calling
> nand_scan(). During the initialization step, the core will consider this
> entry as the default engine for this driver. This value may of course
> be overloaded by the user if the usual DT properties are provided.
>
> Fixes: d525914b5bd8 ("mtd: rawnand: xway: Move the ECC initialization to ->attach_chip()")
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Jan Hoffmann <jan@xxxxxx>
I think you already tested this change and validated it, would you mind
providing your Tested-by?
> Cc: Kestrel seventyfour <kestrelseventyfour@xxxxxxxxx>
> Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
> ---
> drivers/mtd/nand/raw/xway_nand.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/xway_nand.c b/drivers/mtd/nand/raw/xway_nand.c
> index 26751976e502..236fd8c5a958 100644
> --- a/drivers/mtd/nand/raw/xway_nand.c
> +++ b/drivers/mtd/nand/raw/xway_nand.c
> @@ -148,9 +148,8 @@ static void xway_write_buf(struct nand_chip *chip, const u_char *buf, int len)
>
> static int xway_attach_chip(struct nand_chip *chip)
> {
> - chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
> -
> - if (chip->ecc.algo == NAND_ECC_ALGO_UNKNOWN)
> + if (chip->ecc.engine_type == NAND_ECC_ENGINE_TYPE_SOFT &&
> + chip->ecc.algo == NAND_ECC_ALGO_UNKNOWN)
> chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
>
> return 0;
> @@ -219,6 +218,13 @@ static int xway_nand_probe(struct platform_device *pdev)
> | NAND_CON_SE_P | NAND_CON_WP_P | NAND_CON_PRE_P
> | cs_flag, EBU_NAND_CON);
>
> + /*
> + * This driver assumes that the default ECC engine should be TYPE_SOFT.
> + * Set ->engine_type before registering the NAND devices in order to
> + * provide a driver specific default value.
> + */
> + data->chip.ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
> +
> /* Scan to find existence of the device */
> err = nand_scan(&data->chip, 1);
> if (err)
Thanks,
Miquèl
